// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef DEVICE_VR_OPENXR_OPENXR_UTIL_H_
#define DEVICE_VR_OPENXR_OPENXR_UTIL_H_

#include <cstdint>
#include <vector>

#include "base/logging.h"
#include "base/memory/raw_ptr.h"
#include "device/vr/public/mojom/pose.h"
#include "device/vr/public/mojom/vr_service.mojom-forward.h"
#include "device/vr/public/mojom/xr_session.mojom-forward.h"
#include "device/vr/vr_export.h"
#include "third_party/openxr/dev/xr_android.h"
#include "third_party/openxr/src/include/openxr/openxr.h"
#include "ui/gfx/geometry/transform.h"
#include "ui/gfx/geometry/transform_util.h"

namespace device {
// These macros aren't common in Chromium and generally discouraged, so define
// all OpenXR helper macros here so they can be kept track of. This file
// should not be included outside of device/vr/openxr.

#define RETURN_IF_XR_FAILED(xrcode)                                     \
  do {                                                                  \
    XrResult return_if_xr_failed_xr_result = (xrcode);                  \
    if (XR_FAILED(return_if_xr_failed_xr_result)) {                     \
      DLOG(ERROR) << __func__                                           \
                  << " Failed with: " << return_if_xr_failed_xr_result; \
      return return_if_xr_failed_xr_result;                             \
    }                                                                   \
  } while (false)

#define RETURN_VAL_IF_XR_FAILED(xrcode, return_expr)                    \
  do {                                                                  \
    XrResult return_if_xr_failed_xr_result = (xrcode);                  \
    if (XR_FAILED(return_if_xr_failed_xr_result)) {                     \
      DLOG(ERROR) << __func__                                           \
                  << " Failed with: " << return_if_xr_failed_xr_result; \
      return return_expr;                                               \
    }                                                                   \
  } while (false)

#define RETURN_IF_FALSE(condition, error_code, msg) \
  do {                                              \
    if (!(condition)) {                             \
      DLOG(ERROR) << __func__ << ": " << msg;       \
      return error_code;                            \
    }                                               \
  } while (false)

#define RETURN_IF(condition, error_code, msg) \
  do {                                        \
    if (condition) {                          \
      DLOG(ERROR) << __func__ << ": " << msg; \
      return error_code;                      \
    }                                         \
  } while (false)

// Returns the identity pose, where the position is {0, 0, 0} and the
// orientation is {0, 0, 0, 1}.
DEVICE_VR_EXPORT XrPosef PoseIdentity();
DEVICE_VR_EXPORT gfx::Transform XrPoseToGfxTransform(const XrPosef& pose);
DEVICE_VR_EXPORT device::Pose XrPoseToDevicePose(const XrPosef& pose);
DEVICE_VR_EXPORT device::Pose ZNormalXrPoseToYNormalDevicePose(
    const XrPosef& pose);
DEVICE_VR_EXPORT gfx::Point3F ZNormalPositionToYNormalPosition(
    const gfx::Point3F& point);
DEVICE_VR_EXPORT XrPosef GfxTransformToXrPose(const gfx::Transform& transform);
DEVICE_VR_EXPORT XrQuaternionf
GfxQuaternionToXrQuaternion(const gfx::Quaternion& quaternion);
DEVICE_VR_EXPORT mojom::VRFieldOfViewPtr XrFovToMojomFov(const XrFovf& xr_fov);
DEVICE_VR_EXPORT bool IsPoseValid(XrSpaceLocationFlags locationFlags);

bool IsFeatureSupportedForMode(device::mojom::XRSessionFeature feature,
                               device::mojom::XRSessionMode mode);

mojom::XRSemanticLabel ToMojomSemanticLabel(
    XrSpatialPlaneSemanticLabelEXT label);
mojom::XRSemanticLabel ToMojomSemanticLabel(
    XrSceneMeshSemanticLabelANDROID label);

bool IsConvexPolygon(
    const std::vector<mojom::XRPlanePointDataPtr>& polygon);

// Ear-clipping triangulation for simple (non-self-intersecting) 2D polygons.
std::vector<uint32_t> EarClipTriangulate(
    const std::vector<mojom::XRPlanePointDataPtr>& polygon);

// Define a concept for a struct to help validate that it can be safely cast to
// an XrBaseOutStructure.
template <typename XrStruct>
concept ChainableOpenXrStruct =
    offsetof(XrStruct, type) == offsetof(XrBaseOutStructure, type) &&
    offsetof(XrStruct, next) == offsetof(XrBaseOutStructure, next);

// A helper type used to build a next chain of extension structs for OpenXr.
class XrNextChainBuilder {
 public:
  template <ChainableOpenXrStruct XrStruct>
  explicit XrNextChainBuilder(XrStruct* head)
      : head(reinterpret_cast<XrBaseOutStructure*>(head)) {}

  // Add the provided struct to the current next chain. Note that this expects
  // the struct to not currently have any item in it's next chain.
  template <ChainableOpenXrStruct XrStruct>
  void Add(XrStruct* xr_struct) {
    auto* base_struct = reinterpret_cast<XrBaseOutStructure*>(xr_struct);
    CHECK_EQ(base_struct->next, nullptr);
    base_struct->next = head->next;
    head->next = base_struct;
  }

 private:
  raw_ptr<XrBaseOutStructure> head;
};

}  // namespace device

#endif  // DEVICE_VR_OPENXR_OPENXR_UTIL_H_